Hi Srikanth,
What do you mean by property based security?
Anyway, aggregation is done by hierarchy, not by property! And if the user has rights to see Company parent - then it will show total of all children.
Each user can select Options->Sheet Options->Refresh->Calculate Parents in Hierarchies->Set as Default. Then all new reports will have this option enabled.
But it's not the right way of doing things. If you require for some users to see total for a number of companies you can create additional parents and provide appropriate access rights.
B.R. Vadim